Question

字母 T 由两个 $2 \times 4$ 英寸的长方形相邻放置而成，如图所示。这个 T 的周长是多少英寸？

The letter T is formed by placing two $2 \times 4$ inch rectangles next to each other, as shown. What is the perimeter of the T, in inches?

$12$

$16$

$20$

$22$

$24$

答案：C

知识点：周长矩形

难度评级：930

解答：

如果分别计算两个长方形的总周长，会得到 $2(2(2 + 4)) = 2 \cdot 2 \cdot 6 = 24.$

在字母 T 中，它们的相交部分从每个长方形中去掉了一段长度 $2$ 的边。因此 T 的周长为 $24 - 2 \cdot 2 = 20.$

所以正确答案是 C。

If we found the total perimeter of the two rectangles separately, we would have gotten $2(2(2 + 4)) = 2 \cdot 2 \cdot 6 = 24.$

In the letter T, we can see that their intersection removes a piece of length $2$ from each of the rectangles. Therefore, the perimeter of the T is $24 - 2 \cdot 2 = 20.$

Thus, C is the correct answer.

2006 AMC 8 第 6 题

答案：C

难度评级：930

解答：

其他年份的第 6 题